Here is a schematic of the two versions of the Colt that Pietta makes. One has a transfer bar and one does not.
https://www.vtigunparts.com/store/images/1873%20Pietta%20SA.png
Now we need to know if the revolver in question was the coil hand spring version or the transfer bar version. The hand spring version looks like a pull of the hammer to just short of half cock and quick release might push the firing pin hard enough to strike the primer in the cylinder that is currently indexed.
Am I misreading the schematic?
